Lasioglossum (Dialictus) achilleae (Mitchell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 38-39

Lasioglossum (Dialictus) achilleae (Mitchell)

( Figure 45–46 )

Dialictus achilleae Mitchell, 1960: 377 . Ƥ.

Holotype. Ƥ USA, North Carolina, Cruso , June 25, 1934, on Achillea, (T.B. Mitchell) ; [ NCSU]. Examined.

Taxonomy. Krombein, 1967: Lasioglossum (Dialictus) achilleae , p. 462 (catalogue); Hurd, 1979: Dialictus achilleae , p. 1963 (catalogue); Moure & Hurd, 1987: Dialictus achilleae , p. 87; Gibbs, 2010b: Lasioglossum (Dialictus) achilleae Ƥ, p. 49 (redescription, key).

Diagnosis. Female L. achilleae can be recognised by the following diagnostic combination: mesoscutum polished due to lack of microsculpture, punctures sparse throughout; propodeum with strong oblique carina; and metapostnotum delimited from posterior propodeal surface by sharp transverse angle or carina. They are most similar to L. apopkense , which has mesoscutum dull due microsculpture.

Male L. achilleae can be recognised by the following diagnostic combination: F1 short (F2:F1 ratio = 2.5–2.8); mesoscutum polished, punctures sparse throughout ( Fig.46 ); propodeum rugose with strong oblique carina; metasomal terga sparsely punctate, impunctate on apical impressed areas; and metasomal sterna with sparse pubescence. They are most similar to L. apopkense , L. lineatulum , and L. novascotiae . Male L. apopkense have mesoscutum dull due to strong microsculpture. Male L. lineatulum have F1 longer (F2:F1 ratio = 1.6–1.8) and more abundant sternal hairs. Male L. novascotiae have head longer and denser punctures on metasomal terga.

Description. MALE. Similar to female (see Gibbs 2010b) except for the usual secondary sexual characters and as follows. Length 4.50–4.56 mm; head length 1.25–1.45 mm; head width 1.33–1.53 mm; forewing length 3.62–3.80 mm.

Colouration. Flagellum with ventral surface reddish brown. Pterostigma pale brownish yellow. Legs brown, except tarsi pale brownish yellow.

Pubescence. Face below eye emargination with relatively dense tomentum partially obscuring surface, denser on lower paraocular area. Metasomal sterna sparsely pubescent, S3–S4 with small apicolateral tufts (1 OD).

Surface sculpture. Mesoscutum polished, microsculpture faint; punctation sparse between parapsidal lines (i=1–3d) and laterad of parapsidal line (i=1–2d). Propodeal dorsolateral slope coarsely rugose. T2 apical impressed area impunctate.

Structure. Head wide (length/width ratio = 0.94–0.95). Eyes strongly convergent below (UOD/LOD ratio = 1.48– 1.68). Clypeus 2/3 below suborbital tangent, apicolateral margins weakly convergent. Antennal sockets distant (IAD/ OAD> 1.0). Frontal line carinate, ending 1.5 OD below median ocellus. Pedicel subequal to F1. F2 length 2.5–2.8X F1. F2–F10 elongate (length/width ratio = 1.50–1.83). Metapostnotum moderately elongate (MMR ratio = 1.20–1.27), posterior margin sharply angled onto posterior propodeal surface.

Terminalia . Not examined.

Range. Southern Ontario south to south to Georgia. USA: GA, MA, MI, NC, NY. CANADA: ON.

Additional specimens examined. USA: NEW YORK: 1Ƥ333 Albany Co., Colonie, 20.viii.1969, pine barrens, (G. & K. Eickwort); [ CUIC].

DNA Barcode. Available. Single sequence.

Comments. Uncommon.

Figures

FIGURE 45. Lasioglossum achilleae (Mitchell) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 46. Lasioglossum achilleae (Mitchell) male, dorsal view of mesosoma.